/* ===========================
   Common Styles & Utilities
   =========================== */

/* Container */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  width: 100%;
}

/* Section Spacing */
.section {
  padding: var(--spacing-xxxl) 0;
}

.section-small {
  padding: var(--spacing-xl) 0;
}

/* Typography */
.heading-primary {
  font-size: var(--font-size-hero);
  font-weight: var(--font-weight-bolder);
  line-height: var(--line-height-heading);
  color: var(--text-primary);
}

.heading-secondary {
  font-size: var(--font-size-xxlarge);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-heading);
  color: var(--text-primary);
}

.heading-tertiary {
  font-size: var(--font-size-xlarge);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.text-center {
  text-align: center;
}

.text-muted {
  color: var(--text-secondary);
}

/* Section Title */
.section-title {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title h2 {
  font-size: var(--font-size-xxlarge);
  font-weight: var(--font-weight-bolder);
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
  position: relative;
  display: inline-block;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
  border-radius: 2px;
}

.section-subtitle {
  font-size: var(--font-size-large);
  color: var(--text-secondary);
  margin-top: var(--spacing-sm);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 32px;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  line-height: 1.5;
  text-align: center;
  border-radius: var(--radius-medium);
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  outline: none;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-medium);
}

.btn-outline {
  background: transparent;
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

.btn-outline:hover {
  background: var(--primary-color);
  color: white;
}

/* Cards */
.card {
  background: var(--bg-white);
  border-radius: var(--radius-large);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-light);
  transition: all var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-heavy);
  transform: translateY(-4px);
}

/* Grid System */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* Flexbox Utilities */
.flex {
  display: flex;
}

.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}

.flex-between {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.flex-column {
  display: flex;
  flex-direction: column;
}

/* Spacing Utilities */
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

/* Visibility */
.hidden {
  display: none;
}

.visible {
  display: block;
}

/* Image Utilities */
.img-fluid {
  max-width: 100%;
  height: auto;
}

.img-cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Animations */
.fade-in {
  animation: fadeIn var(--transition-slow) ease-in;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Loading Spinner */
.spinner {
  border: 3px solid var(--bg-gray);
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Page Header */
.page-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: var(--spacing-xxl) 0 var(--spacing-xl);
  margin-top: 100px;
}

.page-title {
  font-size: var(--font-size-xxxlarge);
  font-weight: var(--font-weight-bolder);
  margin-bottom: var(--spacing-sm);
  text-align: center;
}

.en-title {
  font-size: var(--font-size-large);
  font-weight: var(--font-weight-normal);
  opacity: 0.9;
  display: block;
  margin-top: var(--spacing-xs);
}

.breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-small);
  margin-top: var(--spacing-md);
}

.breadcrumb a {
  color: rgba(255, 255, 255, 0.9);
  transition: color var(--transition-base);
}

.breadcrumb a:hover {
  color: white;
}

.breadcrumb .separator {
  opacity: 0.6;
}

.breadcrumb .current {
  opacity: 0.8;
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-medium);
  transition: all var(--transition-base);
  z-index: 999;
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-3px);
  box-shadow: var(--shadow-heavy);
}

.back-to-top.show {
  display: flex;
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* Responsive Styles for Page Header */
@media (max-width: 768px) {
  .page-header {
    padding: var(--spacing-xl) 0 var(--spacing-md);
  }

  .page-title {
    font-size: var(--font-size-xxlarge);
  }
}